11601721571 has 32 divisors (see below), whose sum is σ = 13528622592. Its totient is φ = 9844623360.

The previous prime is 11601721561. The next prime is 11601721601. The reversal of 11601721571 is 17512710611.

It is not a de Polignac number, because 11601721571 - 2¹⁰ = 11601720547 is a prime.

It is a super-2 number, since 2×11601721571² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11601721561) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2585696 + ... + 2590178.

It is an arithmetic number, because the mean of its divisors is an integer number (422769456).

Almost surely, 2^11601721571 is an apocalyptic number.

11601721571 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11601721571 is a deficient number, since it is larger than the sum of its proper divisors (1926901021).

11601721571 is a wasteful number, since it uses less digits than its factorization.

11601721571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4763.

The product of its (nonzero) digits is 2940, while the sum is 32.

The spelling of 11601721571 in words is "eleven billion, six hundred one million, seven hundred twenty-one thousand, five hundred seventy-one".